Manufacture of filaments for incandescent electric lamps



(No Model.)

T. A. EDISON. MANUFACTURE OPPILAMBNTS FOR INOANDESGBNT BLEGTRIO LAMPS.-vN0. 470,925 Patented'Mar. 15, 1892.

witmaow gmowtoz $13 4 attozmew 1-: NORRIS versus m, Pnoro'wmm,wAsHmG'roN, o. c,

Uwrrnn STATES ATENT Futon.

THOMAS A. EDISON, OF LLEWELLYN PARK, NEW JERSEY.

MANUFACTURE OF FILAMENTS FOR lNCANDlZSCENT EL ECTRIC LAMPS.

SPECIFICATION forming part of Letters Patent No. 470,925, dated March15, 1892.

Original application filed March 20, 1880, Serial No. 5,864. Divided andthis application filed July 2, 1888. Serial No. 278,852.

(No model.) Patented in England September 16, 1880, No. 8,765 in ItalyNovember 6, 1880, No. 12,315 in Canada November 11,1880,No.11,968; inBelgium November 15, 1880, No. 52,890; in Victoria December 18, 1880,No. 2,936; in Austria-Hungary January 7, 1881; in Queensland February 7,1881 in New Zealand March 7, 1881 No- 510 in Portugal March 31, 1881,No. 661; in New South Wales April 2, 1881; in Spain April 26,1881, No.1,284, and in France June 10,1881,No.

To all whom it may concern:

Be it known that I, THOMAS A. EDISON, a citizen of the United States,residing at Llewellyn Park, in the county of Essex and State of NewJersey, have invented a certain new and useful Improvement in Carbonsfor Electric Lamps and the Manufacture Thereof, (Case No. 780, divisionof Case No. 210,) of which the following is a specification, and whichhas been patented as follows: in Great Britain, No. 3,765, datedSeptember 16, 1880; in Italy, No. 12,315, dated November 6, 1880; inCanada, No. 11,968, dated November 11, 1880; in Belgium, No. 52,890,dated November 15,1880; in Victoria, No. 2,936, dated December 13, 1880;in Austria-Hungary, T 31, f. 50, dated January 7, 1881; in Queensland,February '7, 1881; in New Zealand, No. 510, dated March 7, 1881; inPortugal, No, 661, dated March 31, 1881; in New South WVales, datedApril 2, 1881; in Spain, No. 1,284, dated April 26, 1881, and in'France,No. 111,976, dated June 10, 1881.

As before explained in prior applications for patents for inventions ofmine relating to lighting by electricity, it is essential that theincandescing conductor should be of high resistance and that greatadvantages result from the increase of resistance when such increase canbe obtained without increase in the extent of the radiating surface. Ihave discovered that an incandescing conductor of very high resistancein comparison with the radiating surface may be made by taking severalexceedingly-fine fibers or filaments of carbonizablematerial and weldingthem together prior to carbonization by a suitable cementingcarbonizable liquid. For this purpose I prefer to use naturalfiberssuc'h as bast, jute, manila, hemp, &c.-or other fibers ofendogenous growth made up of a great number of parallel elementaryfiberscemented together by a natural cementing material, which oncarbonization locks all the elementary fibers together into ahomogeneous filament. I take several of these natural fibers,

and after removing the extraneous matter by passing them through acutting-die I form them into a bunch and dip them together into asolution of sugar or other carbonizable liquid and then carbonize themas one fiber, the

carbonizable cementing-liquid binding them firmly together into ahomogeneous filament of high resistance and moderate radiating surface.

The filament and the method of making it is shown in the accompanyingdrawing.

A is a suitable receptacle containing the carbonizable liquid B. Thereceptacle is open at its top. One of its sides is provided with a smallhole a. A number of fine filaments b are taken and their ends passedthrough the hole a from within the box. The filaments are then drawnthrough the carbonizable liquid, and are thus welded into a compactintegral filament c, which may be carbonized in any suitable manner.

In my application, (Case No. 210,) Serial No. 5,864, filed March 20,1880, is described the use of natural fibers for forming oncarbonization the incandescing filaments of electric lamps. Thisapplication, which is of the division of my prior application, (Case No.210,) relates to an improvement upon the invention described in thatapplication.

What I claim as my invention is l. A filament for forming the carbonincandescing conductor of an electric lamp, consisting ofa number ofline filaments welded together by a carbonizable cementing substance,substantially as set forth.

2. A filament for forming the carbon incandescing conductor of anelectric lamp, consisting of a number of natural fibers welded togetherby a carbonizable cementing substance, substantially as set forth.

3. The method of manufacturing incandescing conductors for electriclamps, consisting in uniting by a carbonizable cementing substance anumber of carbonizable filaments and then carbonizing the whole,substantially as set forth.

4. The method of manufacturing incandes- This specification signed andwitnessed this cing conductors for electric lamps, consisting 21st dayof June, 1888. in takin natural fibers removin therefrom r 7 theextrgneous matter, ilniting a number of HIOS' EDISON 5 such fibers by acarbonizable cementing sub- Vitnesses:

stance, and then carbonizing them as one fila- \VILLIAM PELZER, ment,substantially as set forth. A. W. KIDDLE.

